Runner’s World on Running Form

In case you aren’t a subscriber, I wanted to mention that the June edition of Runner’s World (currently on newsstands) includes an article by Peter Vigneron titled “Does Form Matter.” I wanted to thank Peter for including me and my buddy Harry Hollines (the barefoot runner) in the article, and I have to say it was quite a trip to actually do a photo shoot in my little lab. Here’s the picture that was ultimately published in the magazine (that’s my colleague Eric Berry on the treadmill – he’s a far better runner than I!):

As you can see, I don’t have the fanciest lab in the world, but it suits my purposes since for most of my academic life I’ve studied critters smaller than the tip of your pinky finger (tadpoles). I’m a newcomer to the world of running research, but have learned a lot over the past few years, and I’ve enjoyed getting out and filming runners in real world situations (i.e., races). Lab data are valuable, but I also think it’s important that we also take a look at what runners really do when they’re out on the road, and my first academic publication on running is currently undergoing peer review at a scientific journal (a far longer and more involved process than posting on this blog!).

Anyway, I recommend that you check out Peter’s article – he does a very balanced job on a very controversial topic. He also put together a nice video in which he dissects some of my race videos and gives his thoughts on the form of some elites from the Boston Marathon. Check it out below:

This post was authored by Peter Larson. Pete is a recovering academic who currently works as an exercise physiologist, running coach, and writer. He's also a father of three and a fanatical runner with a bit of a shoe obsession. In addition to writing and editing this site, he is co-author of the book Tread Lightly, and writes a personal blog called The Blogologist. Follow Pete on Twitter, Facebook, Google+, and via email.

Comments

It’s certainly cool to see the conversation breaking in to the most mainstream of running publications. But it’s also got to be quite the trip to have a picture in Runner’s World. I’d put a framed copy in every room.

Thanks for posting Peter Vigneron’s video on running form. I was a bit surprised by Peter V. suggesting that Meb’s form as problem included the fact that he lands in from of his center of mass, implying this is a bad thing. While I agree Meb’s form doesn’t look as graceful or efficient as Ryan’s, both of these runners, like everyone else who runs, land in front of their center mass when running at a steady state.

This mistake in the commentary might just be slip, but I do get the sense that Peter V. might under the impression that landing under of center of mass is possible and something to strive for. It might have ben useful for Peter V. to read your and Steve Magnus’ posts on the topic before talking about running form

I don’t know how long this myth about landing and center of mass has been perpetuated in running circles. Is this something that been thought up be Pose and Chi Running authors, or something that predates these?

Thanks for your comments. You correctly note that unless runners are accelerating, they must land slightly in front of their center of mass. I give all the credit to Pete, Steve Magness, and others for making this point clear to me, although I’m not sure it’s a particularly insidious myth to bust. Once you fall over a couple times, you figure out pretty quick that landing directly beneath your center of mass isn’t a workable style of running.

Still, as I’m sure both Pete and Steve would agree, one of the key points of “good” form is landing close to the center of mass. Relative to Hall and some of the other runners Pete’s students filmed, Meb lands farther in front.

On the other hand, as Pete mentioned to me during one of our interviews, Meb’s “bad” form has carried him to an Olympic medal and a major marathon title.

“Still, as I’m sure both Pete and Steve would agree, one of the key points of “good” form is landing close to the center of mass.”

I’ve found the best way to land close to my center of mass is to slip on ice and fall on my butt

I feel the current stress on position of center of mass and landing is somewhat confused and leading the discussion up an wrong avenue. Balance, loading and center of mass are quite subtle topics to understand properly, and very often I see assertions or conclusions that are actually the exact opposite of what is really happening. Visuals cues and actual motion get mixed up too easily as well, all leading to a very confused soup of conflicting ideas.

I believe Pete and Steve tend to stress overstriding as landing with foot infront of knee, rather than in terms of distance in front of the center of mass. This is a good thing, and the correct direction for the debate to take.

“Relative to Hall and some of the other runners Pete’s students filmed, Meb lands farther in front. “

I’ve just looked at the video footage again I don’t think Meb is landing noticably further infront of his center of mass than the other runners like Ryan. Go a look at the footage again and look at the line between the point of first contact and just above the hips (approx. center of mass), this angle is very similar for Meb and Ryan. Meb’s shin bone is very slightly leaning back on impact while Ryan is pretty well vertical, so one might classify Meb as overstridding, but since he’s landing on his heel rather than his mid-foot like Ryan than actual landing position relative to the center of mass is really little different. I really don’t think your assertion that Meb lands further in front of his center of mass is sound based on this video footage.

The missed opportunity in Meb’s running form is that his heel strike doesn’t enable him to elastically store the landing loads in his lower leg so he can’t take advatange of this during push off. Given that heel strikers are still quite common in elites, the extra efficiency affored by a forefoot-mid foot strike can’t be that great. Of course if your an elite then a fraction of a percent might make the difference between winning or coming second

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I think it’s also useful to starting thinking about running form as continium, from elite’s to club runners, the manta about it’s good to land near your center of mass rather kicks dirt into the face of this and is a step backwards. I’ll try to explain what I think are key aspects to think about on this continuim.

First I believe the forefoot/mid-foot strike is better in terms of controlling the onset of loading better and providing greater efficiency due to elastic recoil. Whether you are going easy and just want to minimize loading on your body or an elite what to maximize efficiency this type of landing is good for us.

Second I’d suggest that time on stance vs time in the air is important factor. The peak loads and loading gradients are proportional to (TimeInAir/TimeOnStance +1) {see Pete’s previous posting on analsysi of Boston elite’s and my commentary on G loading} so if you want to run with lowest loading then you want to minimize time in the air, while a longer time on maximizing stance is a good thing. A long time on stance might be good for keeping loads down for club runner, but for the elite racer efficiency will go down as our ability to store energy in our tendons and muscles goes down with time. A long time on stance also means the the more of the loading we generate is horizontal so our force production reduces in efficiency.

There is a big but in this for the elite runner – fatigue, generating large forces required for a small time on stance vs time on air creates more stress on the muscles, tendons and bones. As we could see from Pete’s previous blog positing even amoungst the top elite’s there is huge variation in the TImeInAir/TimeOnStance ratio, so some elite’s seem to be doing better with trading lower loading for slightly lower efficiency.

Now time on stance equates to distance on stance, and with the center of mass somwhere in the middle between landing and toe off we can straight away see that distance of landing in front of mass will go up proportional with time on stance. Given the data on time on stance in Pete’s last posting from the Boston elite’s and how it varies hugely we are forced to come to realization that distance of landing in front of center of mass is also varying widely.

Take a moment for this to sink in. If landing close to the center of mass can vary so widely between elites all performing at a similar level it clearly isn’t a key factor at all. This is obvious once one realizes that a short time on stance (with it landing nearer to center of mass) is a double edged sword – more efficient but greater loads that cause fatigue, it’s something you have to balance, the exact balance is likely to be down to the individual, both in genes and traning and the distance you are running.

I just finish but adding in the cadence is important, as by increasing cadence you can reduce the time on stance while not increasing the TimeInAir/TImeOnStance ratio that is critical to loading, so you can achieve greater efficiency in elastic recoil and waste less energy due to lower horizontal component of force production. Upping cadence is also something that has it’s own natural limits as recovering the leg from toe off to landing position requires it’s own effort and techniques for carrying it out efficiently.

Sorry for long post. Hopefully it’ll help convey why I think horizontal position of center of mass relative to landing is mistaken concept to focus on.

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